Paste tube cap



May 16, 1939- y v. L.; MILLER 2,158,375

PASTE TUBE CAP Filed July 11, v1933 1N VENTOR.

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ATTORNEYS Patented May I6, 1939 UNiTED N STATES z,15s,s":

rAs'l-E 'runnen Vernon L. Miller, Bethel, Kans. A nppucauon July 11,193s, serial No. 218,617

lclalm.

This invention relates to collapsible tubes and especially the captherefor, and the primary object is to provide a closure for paste tubeswhich will automatically open and shut the aperture 5 through which thepaste is extruded when force is exerted upon and released from the tuberespectively. l

g One of the important aims of the invention is the provision of a pastetube cap which may be attached to the conventional type ofv collapsibletube wherein paste is contained, said cap having a spring pressed pistontherein movable to and from a position closing a specially formedaperture, without. being especially manipulated by i5 the operator.

A still further aim of this invention is to provide a paste tube cap ofthe aforementioned character having a minimum number of parts, some ofwhich may be adjustable to alter the tension of the spring therein.

Other objects of the invention will appear during the course of thefollowing'specii'lcation, referring to the accompanying drawing wherein:

Figure 1 is a side elevation of a paste tube equipped withl a capembodying this invention.

Fig. 2 is a fragmentary sectional View through the upper portion of thepaste tube showing the cap in position taken on line II--II of Fig. 1.

Fig. 3 isa View similar to Fig. 2 but with the slidable piston in theaperture-closing position.v Fig. 4 is a cross sectional view through thecap taken on line IV-IV of Fig. 3; and,

Fig. 5 is a lonigtudinal sectional view through another form of the cap.

Fig. 6 is a longitudinal sectional view through a paste tube cap made toembody a modied form of the invention.

One of the problems presented through the use of collapsible tubescontaining paste, is the nature of the caps heretofore employed. Usuallythe cap is a separate unit and becomes misplaced when taken from theneck of the tube. Some efforts have been expended to produce caps ofdiierent natures than those conventionally commercially used but withoutapparent success.

The cap embodying this invention isintended to automatically maintainthe aperture through which the paste is extruded in a closed conditionso long as pressure is not exerted upon .the tube to impart force to thecontained paste sufcient to compress the spring forming a part of thecap. When the results just set down are ob- 55 tained, the past Vwithinthe tube is not Wasted PATENT oi-Flca nor allowed to dry so that aportion thereof becomes useless.

Referring particularly to Figs. 1 to 4 inclusive, it will be apparentthat the illustrated embodiment of the invention is in the nature of ahol- 5 low metal thimble 8 provided with internal screwthreads I0 whichfit upon screw-'threads I2 of the neck of paste tube I4. The open end ofthimble 8 should be slightly enlarged in diameter soA that the innerannular wall 'of thimble 8 is 10 substantially a continuation of theinner annular wall of the neck of tube I4.

Aperture I8 is provided in the side wall of thimble 8 at a pointintermediate the ends thereof. Piston I8 is slidably fitted into thimble8 i5 for movement to and from a position where it closes aperture I6.Piston I8 has a grooved skirt 28 to insure a positive seal and to insurethat paste 22 will not escape into the outer end of thimble 8 pastpiston I8. 0

Spring 24 serves as a means for yieldably hold- 2 ing piston I8 acrossaperture I6. This spring is of such length and nature that it will forcepiston I8 across aperture I6 when pressure upon tube I4 is released bythe operator. Spring 24 25 reaches the limit of its expansion whenpiston I8 is across aperture I'B as shown in Fig. 3, and as soon aspressure is again exerted on tube I 4,'piston I8 will be moved backagainst the force of spring 24 and a ribbon of paste 22 will be ex- 30truded through aperture I6, as illustrated in Fig. 2.

In Fig. 5 an additional element is shown forming a part of the pastetube cap. This element comprises an adjustable plug 30 in screw-thread-35 ed engagement with the outer end of thimble 32 which is but slightlydiierent from the thimble illustrated in Figs. 1 to 4 inclusive.

Internal screw-threads formed in the outer end of thimble 32 engagesscrew-threads 34 of plug ,m 30 and the cavity 36 formed in plug 30receives one end of spring 38, the other end of spring 38 iscircumscribed by the skirt of piston 40 which is yieldably held acrossaperture 42 in precisely the same manner as above described with refer-4fence to Figs. 2 and 3. I

When` it is desired to increase the tension of spring 38, plug 30 ismoved by turning the same on its longitudinal axis. In Fig. 5, plug 30has been moved into thimble 32 as far as the internal 50 screw-threadswill permit, but it is obvious that the length of adjustment may bealtered to suit the desire of the manufacturer.V

Spring 24 or 88, as the case may be, is made stronger or weaker inaccordance with the consistency of paste 22, and when the cap is proper-1y made, the automatic action of opening and closing the aperture of thethimble will occur Without the user of the paste being conscious of anymechanical movement within the specially constructed cap.

The means for returning piston I8 to a position closing aperture I6, maybe manually controllable'. In Fig. 6 is illustrated a modied form of theinvention which includes a rod 50 having one end secured to piston I8and the other end projected exteriorly of cap 8. A head 52 of anysuitable form is carried by the outerend of rod 50 and after the forceof paste 22 has moved both piston 20 and rod 50 along cap 8, so as toopen aperture I6, inward force on head 52 will return the said member tothe point of beginning Where piston 20 is closing aperture I6.

Obviously, the cap and its parts may be made of suitable material, suchas metal or some composition best suited for machining. The cap may bemoved from one tube to another and the parts of the cap may be separatedand cleaned if desired, for they part without the .employment of specialtools.

A large number of changes and modicatons might be made in constructing apaste tube cap that embodies this invention, without departing from thescope of the appended claim.

Having thus described the invention, what ls claimed as new and desiredto be secured by Letters Patent is:

A cap for paste tubes, having externally screwthreaded'necks, comprisinga thimble-like body provided with an aperture through the annular sidewall thereof intermediate the ends; internal threads adjacent to theopen end of the body for engagement with the screw-threads of the tubesto hold the cap in operative position; a piston reciprocably mounted inthe body for movement to and from a position closing the aperture; andmeans for holding the piston in such position, said piston ha ng anannular skirt, the outer face of which in wiping contact with theannular inner face of the said body, said skirt having a plurality ofgrooves formed therein to present a plurality of edges serving to rideover the said face of the body as the piston is reciprocated.

VERNON L. MILLER.

